Abstract. Optical studies of ZnCdSe/ZnSe, ZnCdTe/ZnTe heterostructures with singular and multiple quantum wells and quantum dots arouse interest in connection with investigation of the hot carriers relaxation generated by electron injection or optical excitation. Multi-phonon relaxation of the hot electrons under optical excitation of the quantum-size ZnCdSe/ZnSe heterostructures had been considered before using photoluminescence and Raman scattering [1].